Two Australian children and their father all had gunshot wounds before their car was driven off the wharf at Port Lincoln in South Australia, police have said.
Police said autopsies on Damien Little and his sons revealed they had all been shot before the car entered the water.
A coronial investigation is ongoing and issues including domestic violence and mental health will form part of the report for the coroner.
Police have previously described the incident as a suspected murder-suicide.
Little drove the white station wagon off Brennan's Wharf at high speed early on Monday, plunging into up to 30 metres of water.
A rifle was recovered from the vehicle.
The deaths shocked the local community, where Little was a popular member of a local football team, with Mayor Bruce Green describing it as "one of the saddest days in our history".
A growing memorial of floral tributes and other items such as teddy bears on the wharf has since been moved to a nearby location.
Damien's wife and the boys' mother, Melissa Little, said her husband loved his two children very much.
In a statement about her loss and how she would like her family remembered, she said her husband had been her childhood sweetheart.
"Damien valued and appreciated our close-knit family, he put us first, we were his whole world," she said.
"He spent every hour providing quality time and teaching the boys how to live and grow.
"Damien I loved you so much you have left a huge hole in my heart, our memories I will cherish forever. You will not be forgotten."